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Argyll Robertson Pupils
Argyll Robertson pupils (AR pupils) are bilateral small pupils that reduce in size on a near object (i.e., they accommodate), but do ''not'' constrict when exposed to bright light (i.e., they do not react). They are a highly specific sign of neurosyphilis; however, Argyll Robertson pupils may also be a sign of diabetic neuropathy. In general, pupils that accommodate but do not react are said to show light-near dissociation (i.e., it is the absence of a miotic reaction to light, both direct and consensual, with the preservation of a miotic reaction to near stimulus (accommodation/convergence). AR pupils are extremely uncommon in the developed world. There is continued interest in the underlying pathophysiology, but the scarcity of cases makes ongoing research difficult. Pathophysiology The two different types of near response are caused by different underlying disease processes. ''Adie's pupil'' is caused by damage to ''peripheral'' pathways to the pupil (parasympathetic neuron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specificity (statistics)
''Sensitivity'' and ''specificity'' mathematically describe the accuracy of a test which reports the presence or absence of a condition. Individuals for which the condition is satisfied are considered "positive" and those for which it is not are considered "negative". *Sensitivity (true positive rate) refers to the probability of a positive test, conditioned on truly being positive. *Specificity (true negative rate) refers to the probability of a negative test, conditioned on truly being negative. If the true condition can not be known, a " gold standard test" is assumed to be correct. In a diagnostic test, sensitivity is a measure of how well a test can identify true positives and specificity is a measure of how well a test can identify true negatives. For all testing, both diagnostic and screening, there is usually a trade-off between sensitivity and specificity, such that higher sensitivities will mean lower specificities and vice versa. If the goal is to return the ratio at w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parinaud Syndrome
Parinaud's syndrome is an inability to move the eyes up and down. It is caused by compression of the vertical gaze center at the rostral interstitial nucleus of medial longitudinal fasciculus (riMLF). The eyes lose the ability to move upward and down. It is a group of abnormalities of eye movement and pupil dysfunction. It is caused by lesions of the upper brain stem and is named for Henri Parinaud (1844–1905), considered to be the father of French ophthalmology. Signs and symptoms Parinaud's syndrome is a cluster of abnormalities of eye movement and pupil dysfunction, characterized by: * Paralysis of upwards gaze: Downward gaze is usually preserved. This vertical palsy is supranuclear, so doll's head maneuver should elevate the eyes, but eventually all upward gaze mechanisms fail. * Pseudo- Argyll Robertson pupils: Accommodative paresis ensues, and pupils become mid-dilated and show light-near dissociation. * Convergence-retraction nystagmus: Attempts at upward gaze often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syphilis
Syphilis () is a sexually transmitted infection caused by the bacterium ''Treponema pallidum'' subspecies ''pallidum''. The signs and symptoms of syphilis vary depending in which of the four stages it presents (primary, secondary, latent, and tertiary). The primary stage classically presents with a single chancre (a firm, painless, non-itchy skin ulceration usually between 1 cm and 2 cm in diameter) though there may be multiple sores. In secondary syphilis, a diffuse rash occurs, which frequently involves the palms of the hands and soles of the feet. There may also be sores in the mouth or vagina. In latent syphilis, which can last for years, there are few or no symptoms. In tertiary syphilis, there are gummas (soft, non-cancerous growths), neurological problems, or heart symptoms. Syphilis has been known as "the great imitator" as it may cause symptoms similar to many other diseases. Syphilis is most commonly spread through sexual activity. It may also be transmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parinaud's Syndrome
Parinaud's syndrome is an inability to move the eyes up and down. It is caused by compression of the vertical gaze center at the rostral interstitial nucleus of medial longitudinal fasciculus (riMLF). The eyes lose the ability to move upward and down. It is a group of abnormalities of eye movement and pupil dysfunction. It is caused by lesions of the upper brain stem and is named for Henri Parinaud (1844–1905), considered to be the father of French ophthalmology. Signs and symptoms Parinaud's syndrome is a cluster of abnormalities of eye movement and pupil dysfunction, characterized by: * Paralysis of upwards gaze: Downward gaze is usually preserved. This vertical palsy is supranuclear, so doll's head maneuver should elevate the eyes, but eventually all upward gaze mechanisms fail. * Pseudo- Argyll Robertson pupils: Accommodative paresis ensues, and pupils become mid-dilated and show light-near dissociation. * Convergence-retraction nystagmus: Attempts at upward gaze often p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurosyphilis
Neurosyphilis refers to infection of the central nervous system in a patient with syphilis. In the era of modern antibiotics the majority of neurosyphilis cases have been reported in HIV-infected patients. Meningitis is the most common neurological presentation in early syphilis. Tertiary syphilis symptoms are exclusively neurosyphilis, though neurosyphilis may occur at any stage of infection. To diagnose neurosyphilis, patients undergo a lumbar puncture to obtain cerebrospinal fluid (CSF) for analysis. The CSF is tested for antibodies for specific ''Treponema pallidum'' antigens. The preferred test is the VDRL test, which is sometimes supplemented by fluorescent treponemal antibody absorption test (FTA-ABS). Historically, the disease was studied under the Tuskegee study, a notable example of unethical human experimentation. The study was done on approximately 400 African-American men with untreated syphilis who were followed from 1932 to 1972 and compared to approximately 200 me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miosis
Miosis, or myosis (), is excessive constriction of the pupil. citing: Mosby's Medical Dictionary, 8th ed. The opposite condition, , is the dilation of the pupil. Anisocoria is the condition of one being more dilated than the other. Causes Age * Senile miosis (a reduction in the size of a person's pupil in old age)Diseases * ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marcus Gunn Pupil
A relative afferent pupillary defect (RAPD), also known as a Marcus Gunn pupil, is a medical sign observed during the swinging-flashlight test whereupon the patient's pupils dilate when a bright light is swung from the unaffected eye to the affected eye. The affected eye still senses the light and produces pupillary sphincter constriction to some degree, albeit reduced. Depending on severity, different symptoms may appear during the swinging flash light test: Mild RAPD will presents as a weak pupil constriction initially, after which dilation continues to happen. When RAPD is moderate, pupil size will remain, after which it dilates When RAPD is severe, the pupil will dilate quickly Cause The most common cause of Marcus Gunn pupil is a lesion of the optic nerve (between the retina and the optic chiasm) due to glaucoma, or severe retinal disease, or due to multiple sclerosis. It is named after Scottish ophthalmologist Robert Marcus Gunn. A second common cause of Marcus Gunn p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycloplegia
Cycloplegia is paralysis of the ciliary muscle of the eye, resulting in a loss of accommodation. Because of the paralysis of the ciliary muscle, the curvature of the lens can no longer be adjusted to focus on nearby objects. This results in similar problems as those caused by presbyopia, in which the lens has lost elasticity and can also no longer focus on close-by objects. Cycloplegia with accompanying mydriasis (dilation of pupil) is usually due to topical application of muscarinic antagonists such as atropine and cyclopentolate. Belladonna alkaloids are used for testing the error of refraction and examination of eye. Management Cycloplegic drugs are generally muscarinic receptor blockers. These include atropine, cyclopentolate, homatropine, scopolamine and tropicamide. They are indicated for use in cycloplegic refraction (to paralyze the ciliary muscle in order to determine the true refractive error of the eye) and the treatment of uveitis. All cycloplegics are also mydriat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anisocoria
Anisocoria is a condition characterized by an unequal size of the eyes' pupils. Affecting up to 20% of the population, anisocoria is often entirely harmless, but can be a sign of more serious medical problems. Causes Anisocoria is a common condition, defined by a difference of 0.4 mm or more between the sizes of the pupils of the eyes. Anisocoria has various causes: * Physiological anisocoria: About 20% of population has a slight difference in pupil size which is known as physiological anisocoria. In this condition, the difference between pupils is usually less than 1 mm. * Horner's syndrome * Mechanical anisocoria: Occasionally previous trauma, eye surgery, or inflammation (uveitis, angle closure glaucoma) can lead to adhesions between the iris and the lens. * Adie tonic pupil: Tonic pupil is usually an isolated benign entity, presenting in young women. It may be associated with loss of deep tendon reflex (Adie's syndrome). Tonic pupil is characterized by delayed dila ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adie Syndrome
Adie syndrome, also known as Holmes-Adie syndrome, is a neurological disorder characterized by a tonically dilated pupil that reacts slowly to light but shows a more definite response to accommodation (i.e., light-near dissociation). It is frequently seen in females with absent knee or ankle jerks and impaired sweating. The syndrome is caused by damage to the postganglionic fibers of the parasympathetic innervation of the eye, usually by a viral or bacterial infection that causes inflammation, and affects the pupil of the eye and the autonomic nervous system. It is named after the British neurologists William John Adie and Gordon Morgan Holmes, who independently described the same disease in 1931. Signs and symptoms Adie syndrome presents with three hallmark symptoms, namely at least one abnormally dilated pupil (mydriasis) which does not constrict in response to light, loss of deep tendon reflexes, and abnormalities of sweating. Other signs may include hyperopia due to acc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William John Adie
William John Adie MD Ed., FRCP (31 October 1886 – 17 March 1935) was an Australian-born British physician and neurologist known for describing the Adie syndrome and narcolepsy. Biography William Adie was born in Geelong, Victoria, Australia, on 31 October 1886. He was educated at Flinders Street Model School, but had to leave school to support his family at the age of 13 when his father died in 1899. He worked as an office errand boy, and an employer noticed his ability to learn. He funded evening classes for Adie, who was able to pass the university entrance examination. A doctor in Geelong, Dr. Arthur South, inspired him to study medicine. An uncle in Boston, Massachusetts paid £19 for a one-way ticket for Adie to travel to England to study medicine, which he did at the University of Edinburgh with the help of his uncle and a scholarship. He qualified M.B. Ch.B. in 1911. He became interested in neurology, and worked in Berlin, Vienna, Munich and Paris for a year on a travel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Douglas Argyll Robertson
Douglas Moray Cooper Lamb Argyll Robertson FRSE, FRCSEd LLD (1837 – 3 January 1909) was a Scottish ophthalmologist and surgeon. He introduced physostigmine into ophthalmic practice and the Argyll Robertson pupil is named after him. He was president of the Royal College of Surgeons of Edinburgh. Early life He was born at 58 Queen Street in Edinburgh in 1837, the son of Dr John Argyll Robertson, a surgeon with an interest in surgery of the eye who had served as President of the Royal College of Surgeons of Edinburgh in 1846. His older brother, C. Lockhart Robertson was an eminent psychiatrist and Lord Chancellor's medical visitor. Argyll Robertson was educated at the Edinburgh Institution and at Neuwied in Germany going on to study medicine at the Universities of Edinburgh and St Andrews.MacKay, G. Obituary Douglas Argyll Robertson. ''Caledonian Medical Journal''1909;7:448-454 Career After graduating MD in 1857 from the University of St Andrews, he was appointed house surg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
